Load Specifications
Load data in caliber .300 Rem. Ultra Mag. with .308 | 140gr | Barnes X BT bullet and 70 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are Winchester StaBALL HD, Hodgdon Retumbo and ReloadSwiss RS 76.
Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.
Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 80% and propellant combustion ≥ 95%. Use the sliders above the tables to adjust these thresholds.
Charge: Powder weight in grains. Start with the minimum load and work up carefully.
FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.
MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.
V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.
z (Powder Burn): Estimated propellant combustion percentage at bullet exit.
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Max Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 92% | 56,028 psi | 86% | 3084 fps | 99.9% |
| Accurate 4350 | <<locked>> | 84% | 56,666 psi | 87% | 3133 fps | 100% |
| Accurate MAGPRO | <<locked>> | 92% | 57,943 psi | 89% | 3222 fps | 97.3% |
| ADI AR 2209 | <<locked>> | 90% | 56,536 psi | 87% | 3166 fps | 98.8% |
| ADI AR 2213 | <<locked>> | 94% | 58,421 psi | 90% | 3222 fps | 98.3% |
| ADI AR 2217ᴾ | <<locked>> | 100% | 53,127 psi | 82% | 3114 fps | 97.8% |
| ADI AR 2225ᴾ | <<locked>> | 100% | 48,138 psi | 74% | 3077 fps | 99.4% |
| Alliant Reloder-16 | <<locked>> | 86% | 56,333 psi | 87% | 3176 fps | 100% |
| Alliant Reloder-17 | <<locked>> | 82% | 57,827 psi | 89% | 3192 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 90% | 56,260 psi | 87% | 3153 fps | 98.8% |
| Alliant Reloder-22 | <<locked>> | 94% | 58,798 psi | 90% | 3222 fps | 99.3% |
| Alliant Reloder-23 | <<locked>> | 94% | 56,478 psi | 87% | 3150 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 98% | 56,014 psi | 86% | 3202 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 90% | 57,392 psi | 88% | 3235 fps | 100% |
| Bofors RP15 | <<locked>> | 96% | 58,015 psi | 89% | 3209 fps | 99.1% |
| Bofors RP30ᴾ | <<locked>> | 100% | 56,130 psi | 86% | 3192 fps | 98.5% |
| Bofors RP5 | <<locked>> | 94% | 58,798 psi | 90% | 3222 fps | 99.3% |
| Bofors RP7 | <<locked>> | 84% | 57,972 psi | 89% | 3120 fps | 99.5% |
| Hodgdon H1000ᴾ | <<locked>> | 100% | 58,581 psi | 90% | 3205 fps | 99.1% |
| Hodgdon H414 | <<locked>> | 84% | 57,508 psi | 89% | 3173 fps | 99.7% |
| Hodgdon H4350 | <<locked>> | 82% | 55,956 psi | 86% | 3123 fps | 98.9% |
| Hodgdon H4831 | <<locked>> | 92% | 58,334 psi | 90% | 3159 fps | 97.7% |
| Hodgdon H4831 SC | <<locked>> | 92% | 57,159 psi | 88% | 3140 fps | 97.5% |
| Hodgdon Hybrid 100V | <<locked>> | 88% | 56,971 psi | 88% | 3097 fps | 100% |
| Hodgdon Retumbo | <<locked>> | 98% | 54,868 psi | 84% | 3264 fps | 99.6% |
| Hodgdon Superformance | <<locked>> | 84% | 58,276 psi | 90% | 3199 fps | 99.7% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,289 psi | 57% | 2073 fps | 100% |
| IMR 4350 | <<locked>> | 86% | 55,912 psi | 86% | 3097 fps | 99.3% |
| IMR 4451 Enduron | <<locked>> | 82% | 55,448 psi | 85% | 3084 fps | 99.5% |
| IMR 4831 | <<locked>> | 86% | 56,478 psi | 87% | 3114 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 90% | 55,288 psi | 85% | 3084 fps | 97.3% |
| IMR 7828 SSC | <<locked>> | 94% | 56,492 psi | 87% | 3202 fps | 98.1% |
| Lovex S065 | <<locked>> | 84% | 56,753 psi | 87% | 3094 fps | 100% |
| Lovex S070 | <<locked>> | 86% | 58,624 psi | 90% | 3136 fps | 99.8% |
| Lovex S071 | <<locked>> | 98% | 57,406 psi | 88% | 3104 fps | 100% |
| Norma 204 | <<locked>> | 86% | 57,217 psi | 88% | 3153 fps | 98.8% |
| Norma 217ᴾ | <<locked>> | 100% | 44,135 psi | 68% | 3012 fps | 97.9% |
| Norma MRP | <<locked>> | 90% | 55,187 psi | 85% | 3189 fps | 99.6% |
| Norma URP | <<locked>> | 86% | 57,957 psi | 89% | 3159 fps | 100% |
| Ramshot Grand | <<locked>> | 94% | 57,406 psi | 88% | 3219 fps | 98.6% |
| Ramshot Hunter | <<locked>> | 86% | 56,927 psi | 88% | 3156 fps | 99.9% |
| Ramshot Magnum | <<locked>> | 96% | 56,405 psi | 87% | 3150 fps | 99.5% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,101 psi | 59% | 2123 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 84% | 56,318 psi | 87% | 3140 fps | 100% |
| ReloadSwiss RS 70 | <<locked>> | 86% | 58,291 psi | 90% | 3222 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 98% | 56,289 psi | 87% | 3261 fps | 100% |
| ReloadSwiss RS 80ᴾ | <<locked>> | 100% | 55,796 psi | 86% | 3209 fps | 97.3% |
| Rottweil R 904 | <<locked>> | 90% | 57,667 psi | 89% | 3133 fps | 98.1% |
| Rottweil R 905 | <<locked>> | 90% | 56,115 psi | 86% | 3146 fps | 98.9% |
| Rottweil R 907 | <<locked>> | 84% | 57,972 psi | 89% | 3120 fps | 99.5% |
| Shooters World Long Rifle | <<locked>> | 84% | 56,753 psi | 87% | 3094 fps | 100% |
| Shooters World SW4350 | <<locked>> | 86% | 58,624 psi | 90% | 3136 fps | 99.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 82% | 58,349 psi | 90% | 2992 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 84% | 55,927 psi | 86% | 3035 fps | 99.6% |
| SNPE Vectan Tubal 8000 | <<locked>> | 90% | 55,666 psi | 86% | 3140 fps | 98.8% |
| Somchem S361 | <<locked>> | 88% | 56,057 psi | 86% | 3058 fps | 97.3% |
| Somchem S365 | <<locked>> | 88% | 58,798 psi | 90% | 3163 fps | 100% |
| Somchem S385 | <<locked>> | 90% | 56,971 psi | 88% | 3120 fps | 99.4% |
| Vihtavuori N150 | <<locked>> | 82% | 56,710 psi | 87% | 3038 fps | 100% |
| Vihtavuori N160 | <<locked>> | 84% | 56,072 psi | 86% | 3094 fps | 100% |
| Vihtavuori N165 | <<locked>> | 94% | 56,405 psi | 87% | 3091 fps | 99.2% |
| Vihtavuori N550 | <<locked>> | 84% | 55,506 psi | 85% | 3100 fps | 100% |
| Vihtavuori N555 | <<locked>> | 90% | 55,405 psi | 85% | 3130 fps | 100% |
| Vihtavuori N560 | <<locked>> | 92% | 58,552 psi | 90% | 3238 fps | 98% |
| Vihtavuori N565 | <<locked>> | 96% | 55,622 psi | 86% | 3159 fps | 97.7% |
| Vihtavuori N568ᴾ | <<locked>> | 100% | 56,188 psi | 86% | 3205 fps | 96.8% |
| Winchester 6.5 StaBALL | <<locked>> | 84% | 55,550 psi | 85% | 3038 fps | 100% |
| Winchester 760 | <<locked>> | 84% | 57,508 psi | 89% | 3173 fps | 99.7% |
| Winchester StaBALL HD | <<locked>> | 94% | 54,694 psi | 84% | 3225 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 92% | 56,739 psi | 87% | 3107 fps | 98.9% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 24"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 37,971 psi | 58% | 2753 fps | 97% |
| Accurate 4350 | <<locked>> | 80% | 49,559 psi | 76% | 3018 fps | 99.9% |
| Accurate MAGPRO | <<locked>> | 88% | 50,386 psi | 78% | 3091 fps | 95.5% |
| ADI AR 2209 | <<locked>> | 80% | 40,799 psi | 63% | 2864 fps | 95% |
| ADI AR 2213 | <<locked>> | 86% | 44,831 psi | 69% | 2972 fps | 95% |
| ADI AR 2217 | <<locked>> | 94% | 43,613 psi | 67% | 2927 fps | 95% |
| ADI AR 2225 | <<locked>> | 92% | 37,289 psi | 57% | 2828 fps | 96.1% |
| Alliant Reloder-16 | <<locked>> | 80% | 46,398 psi | 71% | 3015 fps | 99.9% |
| Alliant Reloder-17 | <<locked>> | 80% | 53,954 psi | 83% | 3136 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 80% | 40,959 psi | 63% | 2861 fps | 95.2% |
| Alliant Reloder-22 | <<locked>> | 84% | 42,366 psi | 65% | 2923 fps | 95.8% |
| Alliant Reloder-23 | <<locked>> | 80% | 35,766 psi | 55% | 2772 fps | 99.3% |
| Alliant Reloder-25 | <<locked>> | 80% | 31,473 psi | 48% | 2674 fps | 95% |
| Alliant Reloder-26 | <<locked>> | 80% | 39,682 psi | 61% | 2920 fps | 98.8% |
| Bofors RP15 | <<locked>> | 86% | 42,134 psi | 65% | 2917 fps | 95.6% |
| Bofors RP30 | <<locked>> | 92% | 42,931 psi | 66% | 2949 fps | 95.3% |
| Bofors RP5 | <<locked>> | 84% | 42,366 psi | 65% | 2923 fps | 95.8% |
| Bofors RP7 | <<locked>> | 80% | 51,213 psi | 79% | 3009 fps | 98.6% |
| Hodgdon H1000 | <<locked>> | 90% | 41,814 psi | 64% | 2890 fps | 95% |
| Hodgdon H414 | <<locked>> | 80% | 50,386 psi | 78% | 3054 fps | 98.9% |
| Hodgdon H4350 | <<locked>> | 80% | 52,431 psi | 81% | 3064 fps | 98.3% |
| Hodgdon H4831 | <<locked>> | 86% | 47,718 psi | 73% | 2976 fps | 95.2% |
| Hodgdon H4831 SC | <<locked>> | 86% | 46,876 psi | 72% | 2963 fps | 95% |
| Hodgdon Hybrid 100V | <<locked>> | 80% | 44,208 psi | 68% | 2894 fps | 100% |
| Hodgdon Retumbo | 85.1 gr | 88% | 39,639 psi | 61% | 2936 fps | 95.5% |
| Hodgdon Superformance | <<locked>> | 80% | 50,517 psi | 78% | 3074 fps | 98.8% |
| Hodgdon TrailBoss | <<locked>> | 80% | 27,978 psi | 43% | 1867 fps | 100% |
| IMR 4350 | <<locked>> | 80% | 46,485 psi | 72% | 2933 fps | 97.8% |
| IMR 4451 Enduron | <<locked>> | 80% | 52,170 psi | 80% | 3031 fps | 99.1% |
| IMR 4831 | <<locked>> | 80% | 46,746 psi | 72% | 2953 fps | 99.8% |
| IMR 4955 Enduron | <<locked>> | 86% | 48,892 psi | 75% | 2972 fps | 95.8% |
| IMR 7828 SSC | <<locked>> | 88% | 46,224 psi | 71% | 3012 fps | 95.6% |
| Lovex S065 | <<locked>> | 80% | 50,183 psi | 77% | 2986 fps | 99.6% |
| Lovex S070 | <<locked>> | 80% | 48,791 psi | 75% | 2976 fps | 98.8% |
| Lovex S071 | <<locked>> | 80% | 32,967 psi | 51% | 2631 fps | 95.1% |
| Norma 204 | <<locked>> | 80% | 46,746 psi | 72% | 2966 fps | 96.7% |
| Norma 217 | <<locked>> | 96% | 38,754 psi | 60% | 2887 fps | 96.1% |
| Norma MRP | <<locked>> | 80% | 38,856 psi | 60% | 2874 fps | 96.1% |
| Norma URP | <<locked>> | 80% | 47,906 psi | 74% | 2999 fps | 99.8% |
| Ramshot Grand | <<locked>> | 88% | 46,325 psi | 71% | 3018 fps | 96% |
| Ramshot Hunter | <<locked>> | 80% | 46,746 psi | 72% | 2982 fps | 98.9% |
| Ramshot Magnum | <<locked>> | 86% | 39,334 psi | 61% | 2835 fps | 95.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 28,645 psi | 44% | 1913 fps | 100% |
| ReloadSwiss RS 62 | <<locked>> | 80% | 49,298 psi | 76% | 3028 fps | 99.9% |
| ReloadSwiss RS 70 | <<locked>> | 80% | 47,065 psi | 72% | 3038 fps | 99.7% |
| ReloadSwiss RS 76 | 89 gr | 86% | 36,898 psi | 57% | 2851 fps | 95.7% |
| ReloadSwiss RS 80 | <<locked>> | 96% | 47,979 psi | 74% | 3064 fps | 95.2% |
| Rottweil R 904 | <<locked>> | 82% | 44,802 psi | 69% | 2900 fps | 95.1% |
| Rottweil R 905 | <<locked>> | 80% | 40,422 psi | 62% | 2848 fps | 95.1% |
| Rottweil R 907 | <<locked>> | 80% | 51,213 psi | 79% | 3009 fps | 98.6% |
| Shooters World Long Rifle | <<locked>> | 80% | 50,183 psi | 77% | 2986 fps | 99.6% |
| Shooters World SW4350 | <<locked>> | 80% | 48,791 psi | 75% | 2976 fps | 98.8% |
| SNPE Vectan Tubal 5000 | <<locked>> | 80% | 54,984 psi | 85% | 2946 fps | 100% |
| SNPE Vectan Tubal 7000 | <<locked>> | 80% | 49,400 psi | 76% | 2930 fps | 98.8% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 40,103 psi | 62% | 2844 fps | 95% |
| Somchem S361 | <<locked>> | 84% | 49,211 psi | 76% | 2943 fps | 95.7% |
| Somchem S365 | <<locked>> | 80% | 45,165 psi | 70% | 2953 fps | 100% |
| Somchem S385 | <<locked>> | 80% | 41,292 psi | 64% | 2835 fps | 96.4% |
| Vihtavuori N150 | <<locked>> | 80% | 53,272 psi | 82% | 2992 fps | 100% |
| Vihtavuori N160 | <<locked>> | 80% | 49,226 psi | 76% | 2986 fps | 99.9% |
| Vihtavuori N165 | <<locked>> | 82% | 38,247 psi | 59% | 2753 fps | 95% |
| Vihtavuori N550 | <<locked>> | 80% | 48,936 psi | 75% | 2992 fps | 99.8% |
| Vihtavuori N555 | <<locked>> | 80% | 40,306 psi | 62% | 2861 fps | 99.3% |
| Vihtavuori N560 | <<locked>> | 86% | 47,776 psi | 74% | 3048 fps | 95.5% |
| Vihtavuori N565 | <<locked>> | 90% | 45,585 psi | 70% | 2976 fps | 95.2% |
| Vihtavuori N568 | <<locked>> | 98% | 52,359 psi | 81% | 3140 fps | 95.8% |
| Winchester 6.5 StaBALL | <<locked>> | 80% | 48,559 psi | 75% | 2936 fps | 100% |
| Winchester 760 | <<locked>> | 80% | 50,575 psi | 78% | 3054 fps | 99% |
| Winchester StaBALL HD | 79.4 gr | 80% | 32,416 psi | 50% | 2795 fps | 99.6% |
| Winchester Supreme 780 | <<locked>> | 82% | 40,379 psi | 62% | 2808 fps | 95.1% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 70 powders for .300 Rem. Ultra Mag. loaded with the .308 | 140gr | Barnes X BT. Hodgdon Retumbo delivers the highest muzzle velocity at 3,264 fps; across all powders the maximum-charge window runs from 2,073 fps to 3,264 fps. ADI AR 2217 gives the best case fill at 100 %, and 70 of the 70 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (448 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 140.0 gr projectile in 0.308" calls for a 1:13.5 twist; slower twists will usually not stabilise this weight. ADI AR 2217, ADI AR 2225, Bofors RP30 reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. Winchester StaBALL HD, Hodgdon Retumbo, ReloadSwiss RS 76 rank at the top here: for .300 Rem. Ultra Mag. with the .308 | 140gr | Barnes X BT they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.